1. Field of the Invention
The present invention relates to a mounting equipment for mounting an object on a circular hole. More specifically, the present invention relates to a mounting equipment for mounting and fixing a component for a two-wheeled vehicle, such as a rear view mirror onto an end portion of a pipe shape handle bar or the like.
2. Description of the Background Art
A mounting equipment for fixing a rear view mirror or the like on an end portion of a pipe shaped handle bar or the like of a bicycle has been known. FIG. 9 is an exploded perspective view showing the conventional mounting equipment.
Referring to the figure, the mounting equipment is used for fixing a mirror 15 which is integral with a stay portion 13 on an end portion of a pipe shaped handle bar 7 of a bicycle. The mounting equipment is inserted into handle bar 7, and the equipment includes a tapered nut 33 having its outer surface tapered, a shaft 31 having a cylindrical shape with slits, which expands when it receives at its hollow portion the tapered nut 33, and a screw 11 which fits in tapered nut 33 for engaging shaft 31 and tapered nut 33 which have been drawn into contact. Shaft 31 is formed integral with stay portion 13.
FIG. 10 is a perspective view showing appearance of shaft 31 shown in FIG. 9. Referring to the figure, shaft 31 has a cylindrical shape, and has slits 17a to 17d at a side to be engaged with the tapered nut 33. At portions sectioned by slits 17a to 17d, plates 35a to 35d having arcuate cross section (hereinafter referred to as arcuate plates) result.
FIG. 11 is a perspective view showing an appearance of tapered nut 33 shown in FIG. 9.
Referring to the figure, tapered nut 33 has a tapered shape, that is, it has smaller diameter at a side to be engaged with shaft 31, and larger diameter at the opposite side. Further, tapered nut 33 is provided with rotation inhibiting projections 37a and 37b which are engaged with slits 17a and 17c or slits 17b and 17d of shaft 31 shown in FIG. 10 for inhibiting relative rotation of tapered nut 33 and shaft 31.
Further, there is provided a tapped hole 43 for engagement with screw 11 axially through tapered nut 33 along the direction of extension of shaft 31.
Mirror 15 integral with stay portion 13 is mounted on handle bar 7 by the mounting equipment in the following manner.
Referring to FIG. 9, first, tapered nut 33 and shaft 31 are engaged by means of screw 11, with rotation inhibiting projections 37a and 37b of tapered nut 33 engaged with slits 17a and 17c or 17b and 17d of shaft 31. In this state, the mounting equipment consisting of tapered nut 33 and shaft 31 is inserted into handle bar 7. FIG. 12 shows a cross section taken along the line X--X in this state. Here, tapered nut 33 is simply in contact with arcuate plates 35 of shaft 31, and the shape of the arcuate plates 35 of shaft 31 is not deformed.
From this state, screw 11 is screwed in, so that tapered nut 33 is pushed into shaft 31, and at the same time arcuate plates 35 of shaft 31 are pushed and expanded by tapered nut 33. Consequently, tapered nut 33, arcuate plates 35 and inner portion of handle bar 7 are brought into contact with each other, whereby stay portion 13 and handle bar 7 are firmly engaged.
However, the conventional mounting equipment has a disadvantage that it is susceptible to damage, from reasons described in the following.
FIG. 14 is a cross sectional view taken along the line Y--Y of shaft 31 shown in FIG. 9.
As it is apparent from the figure, shaft 31 has a discontinuous circular cross section as there are slits 17a to 17d. Further, since it must be deformed as the tapered nut 33 is inserted therein, it is made unavoidably thin, that is, it has small cross sectional area. Therefore, shaft 31 does not have high strength.
Referring to FIG. 13, with the screw 11 fully screwed, shaft 31 comes into contact with the inside of handle bar 7 at the tip ends of arcuate plates 35. Therefore, when one grabs or touches stay portion 13 while he or she is riding on the bicycle and a torque as an external force is applied to shaft 31 with screw 11 serving as axial core, there would be torsional moment acting on arcuate plates 35. This torsional moment causes breakage or damage of shaft 31 which has small cross sectional area as described above.
In order to prevent such damage, there are two possible methods. Namely, a method in which the screw is fastened loose so as to easily allow sliding rotation of the inside of the handle bar with respect to the outer side of the shaft, and a method in which a mechanism dividing the stay portion and shaft portion by separate parts so that even when torque is applied to the stay portion, only the stay portion rotates and the torque is not transmitted to the shaft portion, is incorporated in the mounting equipment. However, no matter which method is employed, when one happens to touch the stay portion or the like while he or she is riding on the bicycle, the mirror is displaced easily, which is not convenient for use. In this case, it goes without saying that it is impossible to drive the bicycle while gripping the stay portion 13. If the latter method is employed, it is necessary to separately prepare and incorporate the mechanism allowing rotation of the stay portion only. Therefore, the number of parts is increased, and hence the cost is increased.
The present invention was made to solve the above described problems and its object is to provide a mounting apparatus which requires a smaller number of parts, and is less susceptible to damage.
The mounting equipment in accordance with the present invention is for mounting an object on a mount base component having a hollow portion of approximately circular cross section, which equipment includes a first bar shaped mounting part to be connected to the object to be mounted; a second mounting part having a tip end of such a shape that covers at least an end portion of the first mounting part, to be engaged with the first mounting part with tip end expanded conforming to an outer shape of the first mounting part as it is drawn closer to the first mounting part; a drawing part capable of drawing the first and second mounting parts relative to each other; wherein first and second mounting parts in mutually engaged state are inserted to the hollow portion of the mount base component, and the drawing part is activated so that tip end of the second mounting part is pressed against the inner wall of the hollow portion of the mounting base component.
In the mounting equipment in accordance with the present invention, the first and second mounting parts in mutually engaged state are inserted to the hollow portion of the mount base component, and the first and second mounting parts are drawn close to each other by the drawing parts. Therefore, the tip end of the second mounting part is expanded conforming to the outer shape of the first mounting part, and the tip end of the second mounting part is pressed against the inner wall of the hollow portion of the mount base component. Therefore, the equipment can be made durable and less susceptible to damages.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.